Sprinkler head having adjustable precipitation rate



v July 8, 1969 E. J. HUNTER 3,454,225

SPRINKLER HEAD HAVING ADJUSTABLE PRECIPITATION RATE Filed March so.1967, v I Sheet of 2 IV'IA/A II/III/III/I All lNl/E'A/TOE EDWIN J.HUNTEE JYWE/QMW July 8, 1969 J. HU NTER A 3,454,225

I SPRINKLER HEAD HAVING ADJUSTABLE PRECIPITATION RATE Filed March so,1967 A Sheet 2 of 2 INVEN r02 v [ROW/IV J Hem/r52 y 44M 541M UnitedStates Patent U.S. Cl. 239-205 9 Claims ABSTRACT OF THE DISCLOSURE Aspray head for an irrigation sprinkler having a plurality of angularlyspaced discharge orifices characterized by similar, generally triangularexit sections, each bounded by converging sides defining an apex, and abase side opposite the apex; and means for adjusting the spacing betweenthe apices and base sides of the respective exit sections to vary theeffective areas of these sections without altering their geometricproportions, thereby to regulate the precipitation rate of the sprinklerwithout appreciably affecting its overall coverage, spray pattern, orwater distribution within the spray pattern. An improved pop-upsprinkler embodying the spray head and adapted for use in a permanentunderground sprinkler system.

Background of the invention This invention relates generally toirrigation devices, and more particularly to an improved sprinkler headhaving novel, generally triangular discharge orifices which areadjustable to vary the precipitation rate of the spray head withoutappreciably altering its overall coverage, spray pattern, or waterdistribution within the spray pattern. The invention relates also to animproved pop-up sprinkler embodying the spray head and adapted for usein a permanent underground sprinkler system.

A wide variety of irrigation sprinklers have been devised. The existingsprinklers, however, are characterized by certain inherent deficiencieswhich the present invention seeks to overcome. Generally speaking,irrigation sprinklers may be classified as either fixed discharge, ormoving discharge, sprinklers. A typical fixed discharge sprinkler has anormally stationary spray head which directs either a number of discretediverging streams of water, or a generally continuous fan-shaped sprayof water spreading outwardly from the spray head over a given anglewhich may range from a few degrees to a full 360, depending upon thearea to be covered. A moving discharge sprinkler, on the other hand, hasa movable spray head, which directs one or more water streams outwardlyfrom the head in a given direction, or directions, relative to the head,and which is driven in a rotary, oscillatory, or other cyclic motion tocause the water streams to sweep over the area to be irrigated.

Moving discharge sprinklers are superior to the fixed discharge typefrom the standpoint of low precipitation rate, and a moving dischargesprinkler may be designed to distribute a relatively small flow of waterover a relatively large area. The existing fixed discharge sprinklers,on the other hand, continuously deliver a relatively large flow of waterto a relatively small area and thus produce a relatively highprecipitation rate over the area. However, moving discharge sprinklerstend to be complex in construction, costly to manufacture, subject towear and malfunction, sensitive to water-flow rates and pressures, andtheir coverage is adversely affected by wind. Moreover, these sprinklersare ill-suited to small and/0r irregularly shaped areas, and aregenerally incapable of accurate trimming, that is, spraying along butnot ap- "ice preciably beyond the border of an irrigation area,particularly an irregular border. Accordingly, moving dischargesprinklers are not totally satisfactory for many uses, notably inpermanent underground lawn sprinkler systems.

Fixed discharge sprinklers, on the other hand, are characterized bymaximum simplicity, low cost, reliability, immunity to wear, and theability to irrigate small or irregular areas and to accurately trim theborders of such areas. The chief disadvantage of fixed sprinkler headsis that they are relatively inflexible with respect to varying theprecipitation rate. This is an important disadvantage when it isconsidered that the water requirements of a yard are not the same overits entire area. One area may require more water than another owing todifferences in drainage, plant coverage, root density in the soil, andexposure to sun and wind. Fixed sprinklers are usually operated ingroups from a common control valve, which may be manually controlled oroperated by an automatic controller. In either case, all of thesprinklers in a group go on and off together, and therefore run for thesame length of time. Consequently, they all deliver approximately thesame amount of water to their respective areas of coverage, with theresult that some areas requiring less water are overwatered, while otherareas requiring more water are underwatered.

Various attempts have been made in the past to provide means foradjusting the precipitation rate of the individual sprinkler heads, sothat the distribution of water can be tailored to the needs of the yard.One such attempt has been to provide means (usually in the form of anadjustable valve upstream from the sprinkler head) for varying the waterpressure to each sprinkler head. The disadvantage of this approach isthat the volume of water delivered by a sprinkler head is proportionalto the square root of the pressure. At the same time, the spray patternis greatly influenced by water pressure. Reducing the pressureappreciably below the optimum results in coherent streams without properbreakup, whereas increasing the pressure much above optimum results inexcessively fine breakup of the stream, giving a fine mist which driftswith the slightest wind. For example, a sprinkler head which is designedto deliver 2.0 g.p.m. at 20 p.s.i., will deliver 1.75 g.p.m. at 15p.s.i., or 2.45 g.p.m. at 30 p.s.i. This is only slightly greater than50 percent more volume at 30 p.s.i. than at 15 p.s.i., and is achievedat the expense of the spray pattern, which is adversely affected by suchvariation in pressure. Moreover, the water requirements of differentareas in a yard may vary by as much as 3 to 1, and it is thereforeobvious that adjusting the volume of a sprinkler head by varying thewater pressure is totally impractical.

Another attempt to vary the output of a sprinkler head has been to varythe diameters of the spray orifices. This has not been satisfactory,however, as small orifices tend to deliver fine, coherent streams ofwater which do not break up into a uniform spray pattern, and the smallorifices are subject to liming up rapidly.

Thus, there has heretofore been no satisfactory means for regulating theprecipitation rate of individual sprinkler heads over a wide range andwithout adversely affecting the spray pattern, so that a group ofsprinkler heads operating simultaneously can be adjusted to delivervarying rates of precipitation to different parts of the yard accordingto the specific needs of their respective areas of coverage.

Summary of the invention The primary object of the invention is toprovide an improved fixed discharge irrigation sprinkler head, which isadjustable over a relatively wide range of discharge volumes, to varythe precipitation rate according to the water needs of the area covered,without appreciably altering the overall coverage of the head, its spraypattern, or the water distribution within the spray pattern.

Another object of the invention is to provide an improved fixeddischarge adjustable sprinkler head of the character described, which iscapable of producing a well broken up spray pattern, even at the minimumflow rate.

A further object of the invention is to provide an improved pop-upsprinkler embodying a spray head of the character described, and whichis characterized by optimum simplicity of construction, economy ofmanufacture, and reliability of operation.

Other objects, advantages, features of the invention will become readilyapparent to those skilled in the art as the description proceeds,

Description of the drawings FIGURE 1 is a side elevation of an improvedpop-up sprinkler according to the invention, illustrating the sprinklerinstalled in a permanent underground sprinkler system and the novelfixed discharge spray head of the sprinkler in its extended position;

FIGURE 2 is an enlarged axial section through the pop-up sprinkler ofFIGURE 1, illustrating in solid lines, the spray head in its retractedposition within the sprinkler, and in phantom lines, the spray head inits extended position;

FIGURE 3 is a greatly enlarged fragmentary sectional view, taken at 33in FIGURE 2;

FIGURE 4 is an enlarged axial section through the upper extremity of thesprinkler head of the invention;

FIGURE 5 is a side elevation, slightly reduced in scale, showing anadjustable cap embodied in the sprinkler head of FIGURE 4;

FIGURE 6 is a bottom plan view of the sprinkler head cap, taken on theline 6 6 in FIGURE 5;

FIGURE 7 is a view similar to FIGURE 6, illustrating the cap of amodified sprinkler which emits a water spray through an angleapproximating 270";

FIGURE 8 is a view similar to FIGURE 6, illustrating the cap of afurther modified sprinkler head, which emits a water spray through anangle approximating 180;

FIGURE 9 is a view similar to FIGURE 6, illustrating the cap of afurther modified sprinkler head, which emits a water spray through anangle approximating 90;

FIGURE 10' is a side elevation, on a slightly reduced scale, of theupper end of the sprinkler head in FIGURE 4, which shows the headadjusted to deliver water at the maximum rate of precipitation;

FIGURE 11 is a view similar to FIGURE 10, illustrating the sprinklerhead cap adjusted to deliver water at a very low precipitation rate;

FIGURE 12. is a horizontal section, taken on line 12- 12 in FIGURE 4;and

FIGURE 13 is an enlarged fragmentary sectional view, taken at 13-13 ofFIGURE 11, illustrating in particular, the action of a deflector ring inthe spray head, which is designed to disperse or break up the wateremerging from the sprinkler head at relatively low flow rates.

Description of the preferred embodiment One important aspect of theinvention is concerned with an adjustable volume sprinkler head having aspray pattern, the distribution of which is ideally suited to the usualsprinkler head layout wherein the circles of coverage of separatesprinkler heads in a group overlap to some extent, and in which the areaof coverage and spray pattern are not appreciably affected by varyingthe precipitation rate. In general terms, this sprinkler comprises aspray head, represented in the drawings by the spray head 10, having awater passage 12 opening to the ex terior of the head and connected to asource of water under pressure, and at least one discharge orifice 14communicating with the passage to direct streams of water outwardly fromthe spray head. The orifice 14 is characterized by an effective exitsection 16 of generally triangular shape bounded by converging sides 18which define an apex 20 and a base side 22, opposite the apex. Orifice14 is thus effective to discharge a water stream which has a generallytriangular cross-section as it emerges through the orifice exit section16. Orifice adjusting means 24 are provided for adjusting the spacingbetween the apex 20 and side 22 of the exit section, by relativemovement of the apex and base side toward and away from one anotheralong a direction line normal to the base side and passing through theapex, thus to vary the effective area of the exit section, withoutaltering its geometric proportions. In the particular spray head 10illustrated, the converging sides 18 of the orifice section 16 meet todefine the apex 20 which, accordingly, is relatively sharp. It willbecome evident from the ensuing description, however, that the apex 20*may be relatively flat or rounded to some degree. Accordingly, it willbe understood that the expression apex as used herein, is intended toencompass all of these various apex configurations,

While a spray head embodying the invention might conceivably have asingle discharge orifice 14-, a typical spray head will have amultiplicity of circumferentially disposed orifices. These severalorifices are substantially identical in shape and have essentiallyidentical, generally triangular exit areas 16. The orifice adjustingmeans 24 is effective to adjust the effective areas of the severalorifice exit sections 16 simultaneously without altering their geometricproportions, and in such a way that the several exit sections havesubstantially equal areas in all positions of adjustment. As will appearfrom the ensuing description, the several orifices of the spray head arecircumferentially spaced about the spray head in such a way as toprovide the head with the desired spray pattern. The illustrated sprayhead 10, for example, has 16 orifices which are uniformly spaced aroundthe circumference of the head to provide the latter with a full 360*spray pattern. FIGURES 7, 8 and 9 illustrate modified orificearrangements which provide efiective spray patterns of 270, 180 andrespectively. In some cases, a spray head according to the invention maybe provided with two diametrically opposed groups of orifices, whichprovide the head with two separate, oppositely directed spray areas orpatterns. A spray head of this latter type, for example, is useful forwatering long, narrow areas.

During operation of the sprinkler, water flows upwardly through passage12 and issues laterally through the orifices 14 in a number of divergentwater streams that have triangularly-shaped cross-sections as theyemerge from the orifice sections 16. Each of these streams breaks upinto a spray of relatively fine drops as it recedes from the head,forming an evenly dispersed, conical spray pattern of approximately 22/2 degrees angular spread. The rate of flow through each of the orifices16 (and therefore the head as a whole) may be regulated over aconsiderable range, of the order of 10 to 1, by adjustment of theorifice-adjusting means 24 to regulate the eifective areas of theorifice exit sections 16.

As explained earlier, a second aspect of the invention is concerned withan improved pop-up sprinkler embodying the adjustable spray head. Ingeneral terms, this popup sprinkler, which is designated in its entiretyby the reference numeral 24, comprises a cylindrical housing 26 having alower inlet 28 for connection to a source of water under pressure, andan upper opening 30 slidably receiving the spray head 10. The spray headis normally retracted in its solid-line retracted position as shown inFIGURE 2, by a spring 32, and is extended to its brokenline position byWater pressure. When retracted, the upper end of the spray headcontaining the discharge orifices 14 is disposed within the opening 30,substantially flush with the upper end of the housing 26. Within thehousing is a strainer 34, of unique construction, which removesparticles and other foreign matter from the water flowing to the sprayhead, that otherwise might block the spray head orifices 14.

Referring now to FIG. 4, spray head is seen to comprise inner and outerslidably telescoping members 36 and 38. The inner member 36 has a numberof V-shaped openings, or slots 40, formed in its bottom end, whichcommunicate with the water passage 12, and have their apex endsextending beyond one edge of the outer member 38 to define a series ofspray head orifices 14. At its upper end, the member 38 has an annularedge 42, which extends across the openings 40 to define the base sides22 of the orifice exit sections 16. Orifice adjusting means 24 iseffective to adjust the members 36, 38 axially with respect to oneanother and thereby regulate the effective areas of the triangularorifice exit sections 16 without altering their geometric proportions.The exit sections of the illustrated orifices conform to isoscelestriangles, the medial planes of which, i.e., planes normal to the basesides and passing through the apices, contain the longitudinal axis ofthe members 36, 38.

In the particular spray head 10 illustrated, the outer telescopingmember 38 is a generally tubular body containing the water passage 12.The lower end of this body is open and flared outwardly to form ashoulder 44. The upper end of the body is also open, and is counterboredat 46. Inner telescoping member 36 is, essentially, a cap having aclosed upper end and an open lower end, fitting slidably with lightfrictional fit, within the counter-bore 46 of the outer member. The caphas a main, generally cylindrical body 48, the upper end of which isexternally reduced to form a body extension 50. Fitted on and cementedt0 the body extension 50 is a cover 52, having a radial sealing flange54 about its upper end. Below this flange, the cover has substantiallythe same external diameter as the cap body 48. The upper end face of thebody extension 50 and the top wall of the cap cover 52 are axiallyspaced, to define therebetween a chamber 56. The cover 52 has a centralhole 58, opening into this chamber.

The orifice adjusting means 24 of the illustrated spray head comprises atubular, internally threaded stem 60, which is firmly joined at itslower end by a number of angularly spaced, radial spokes 66 to the upperend of tubular member 38, just below the counterbore 46. The stem 60extends axially beyond the upper end of member 38 and passes through acentral bore 68 in the spray cap body 48, in free-sliding engagementtherewith. Threaded into the stem 60 is an adjustment screw 70, theshank of which extends through a reduced opening 72 in the upper end ofthe cap body extension 50, and a head 74 which is located within the capchamber 56. The slot in screw head 74 is accessible through opening 58,for engagement with a screwdriver or the like. It is evident thatrotation of the screw 70 causes the spray head cap to be adjustedaxially relative to the spray head body 38.

The lower end of the spray head cap 36 has a number of pointed,downwardly narrowing, tooth-like formations 76 which define therebetweenthe V-shaped slots 40. Each tooth has an outer surface 78 with acylindrical curvature conforming to that of the outer surface of the capbody 48, and two planar side faces 80, which con-verge inwardly towardthe central axis of the cap. These side faces of each tooth formationmeet along a relatively sharp meeting edge 82. As best shown in FIG. 4,the meeting edges 82 extend at acute angles relative to the cap axis andlie in a common conical plane generated about the axis. The toothformations 76 thus have a three-sided, generally pyramidal shape. Thetooth formations 76 are integrally joined along their radially inneredges to a coaxial, externally conically tapered sleeve 83, whichprojects downwardly from the under side of cap body 48. This sleeveslides on threaded stem 60, and defines, with the surrounding wall ofspray head body 38, an effective, tapered annular inlet connecting thewater passage 12 to the orifices 14. It is now evident, therefore, thatthe orifices 14 open laterally to the exterior of the spray head throughtheir exit sections 16, and axially to the water passage 12 through theannular inlet defined between the spray head body 38 and the cap sleeve81. For reasons to be explained presently, the cap 36 mounts a spraydeflector or dispersing ring 84 having a lower, annular beveled edgeface 86. This ring is preferably adjustable axially relative to the cap,as by threading the ring on the cap body 48 in the manner shown,although it might be fixed, as will be explained hereinafter.

Housing 26 has a central bore defining a cylindrical chamber 88, withinwhich are contained the strainer 34, spring 32, and pop-up spray head10. Projecting downwardly from the bottom end of housing 26 is a stem90, through which the inlet 28 passes, and stem is adapted "forconnection to a fitting, such as the illustrated tee coupling 92. Theupper end of housing 26 is externally threaded to receive a removablecap 94, and spray head opening 30 extends centrally through this cap.

The strainer 34 within housing 26 comprises a perforate, generallycylindrical, cup-shaped body 96, the upper end of which has an outwardlydirected radial sealing flange 98. Sealing flange 98 extends out acrossthe upper annular edge of housing 26, and is clamped between the latteredge and the housing cap 94. The strainer body is constructed of aplastic, which is somewhat elastic, so that the strainer flange 98yields slightly under the clamping pressure exerted on the flange by cap94, to provide an effective seal between the cap and the sprinklerhousing 26. This sealing feature of the strainer flange may be enhancedby providing the flange with an upstanding annular sealing ridge 98a,for seating against the cap, as shown. Preferably the cylindrical wall96 of the strainer 34- has a number of axially spaced, circumferentiallyextending, reinforcing ribs 34a formed on its outer surface, and cutthrough the wall between the ribs 34a is a large number of angularlyspaced, very narrow, longitudinally extending slots 99 (see FIG. 3),through which the water flows in passing from chamber 88 to the interiorof spray head 10. Slots 99 serve as very fine strainer passages, butbecause of their great number, they offer little resistance to the flowof water. As best seen in FIG. 2, the strainer surrounds and is coaxialwith spray head 10 when the latter is retracted, as shown in solid linesin the drawing. In this regard, it will be recalled that tthe spray headslides vertically through the opening 30 in sprinkler cap 94 in movingbetween its extended and retracted positions. Spring 32, which yieldablyreturns the spray head to its retracted position, surrounds the sprayhead be tween the latter and the strainer 34. At its lower end, thespring seats against lower spray head shoulder 44, and at its upper endagainst the under side of the housing cap 94. Retraction of the sprayhead is limited by the upper spray head flange 54, which seats againstthe upper surface of the cap, as shown. Extension of the spray head islimited by engagement of the shoulder 44 with the bottom end of a sleeve100, which projects downwardly from the upper side of housing cap 94 andsurrounds and defines the cap opening 30.

When the spray head I10 has less than a full 360 spray pattern, such asthe spray patterns produced by the ori fice arrangements of FIGURES 7through 9, it is necessary to restrain the spray head against rotationon its central axis relative to the sprinkler housing 26. This may beaccomplished in various ways. In the particular spray head illustratedin the drawings, the spray head flange 44 has a notch 101 formed in itsouter edge, which slidably engages a longitudinal key 102 projectinginwardly the inner surface of the cylindrical wall of the strainer 96along one side thereof. As its flange 98 is tightly clamped between thecap '94 and the top edge of the housing body 26, the strainer 96 isthereby held against turning, and the engagement of the key 102 in notch101 therefore prevents turning of spray head 10.

The pop-up sprinkler 24 is designed for use in an underground sprinklersystem, such as that shown in FIG. 1. When installed, the sprinkler isburied to the level indicated, wherein its cap 94 is substantially flushwith the ground. Normally, the spray head of the sprinkler is retractedinto the sprinkler housing. The head is then shielded against damage,and its upper rim is substantially flush with housing cap 94 so as notto interfere with persons or objects on the surface. Moreover, seatingcontact of the spray head flange 54 with sprinkler housing cap 94effectively seals the cap opening 30 against the entrance of dirt, andother debris into the strainer 96. Perhaps even more importantly, itseals the sprinkler head against leakage of water out of the body 26,due to draining of the system from sprinkler heads at higher elevationswhen the water has been turned off. This is an important feature of thepresent invention, as it prevents evaporation of water from the sprayhead, with consequent deposit of lime on the outer surface of the sprayhead body 10 and in the orifices 16. Lime deposits on the spray headbody would cause sticking, which might interfere with the pop-up action,while deposits in the orifices 16 would affect both the spray patternand the volume of water delivered by the sprinkler head. By sealing theopening 30 and keeping the chamber 88 filled with Water, the sprinklerhead 10 is kept constantly submerged in water which prevents formationof deleterious lime deposits thereon.

When water under pressure is delivered to the sprinkler 24, the pressureof the water urges the spray head 10 to its extended position. In thisposition, the lower spray head shoulder 44 seats against the lower endof the cap sleeve 100, to seal the spray head to the sleeve. Waterentering the spray head flows upwardly through its passage :12 and isthen discharged laterally, or radially, from the orifices 16 to irrigatethe surrounding area. As noted earlier, the spray head member 36 has afull 360 spray pattern. The orifice arrangements embodied in themodifified spray head members 36a, 36b and 360 of FIGURES 7 through 9produce, respectively spray patterns of 270, 180 and 90 angular extent.Various other orifice arrangements are possible, such as that referredto earlier, which includes two diametrically opposed groups of orificesfor watering relatively long narrow areas.

The several water streams issuing through the spray head orifices 14have generally triangular cross-sections as they emerge from thetriangular orifices 16. These triangular orifices, and the triangularwater streams produced thereby, have several advantages. Thus, it hasbeen found that the water streams emerging from the spray head break upand disperse in a more effective manner, giving a distribution patternthat is particularly wellsuited to the usual sprinkler head layout,wherein the area covered by each head overlaps the areas of adjacentheads. In a typical spray head according to the invention, for exmple,each orifice 16 covers an arc of approximately 22 /2 degrees, wherebythe spray head having a full 360 spray pattern, such as spray head 10,will have 16 uniformly circumferentially spaced orifices. Spray headshaving the modified caps of FIGURES 7 through 9 will have a reducednumber of orifices proportional to the angular extent of theirrespective spray patterns.

Another and highly important advantage of the triangular shape of theorifice exit sections 16 resides in the fact that the effective areas ofthese sections, and hence the precipitation rate of the spray head as awhole, may be regulated over a substantial range, typiclly n the orderof a 1 ratio, without altering the geometric proportions of the exitsections. Regulation of the effective areas of the exit sections, ofcourse, is accomplished by rotating the adjusting screw 70 in onedirection or the other, to retract the cap into or extend the cap fromthe tubular spray head body 38. This adjustment of the cap is effectiveto adjust the spacing between the apices 20 of the orifice exit sections16 and the upper edge 42 of the spray head body 38, which defines thebase sides 22 of the exit sections, thus to vary the effective areas ofthe sections. FIGURES 10 and 11 illustrate two different positions ofadjustment of the cap 36 corresponding, respectively, to a maximumprecipitation rate and a minimum precipitation rate. It has been foundthat this adjustment of the effective areas of the orifice exit sectionsWithout altering their geometric proportions is effective to regulatethe precipitation rate of the sprinkler head Without appreciablyaltering its coverage, spray pattern, or the distribution of waterthroughout the spray pattern.

A further distinct advantage of the triangular exit sections 16 of thespray head orifices 14 is that the exit sections may be restricted, asin FIG. 11, to produce a spray of extremely low flow rate which is atthe same time, well broken-up and uniformly dispersed throughout thespray pattern. Thus, even at extremely low flow rates, the present sprayhead does not discharge coherent water streams which might tend to erodethe soil at the points of impact of the streams with the soil, as do theexisting irrigation sprinklers. The deflector ring 84 of the presentspray head aids in the break-up and dispersion of the Water streamsemerging from the spray head at low flow rates. In FIG. 13, it will beobserved that the velocity components, indicated by the arrows V1 andV2, of the water streams emerging through the orifices, cause thestreams to issue in an outward and upward direction. Deflector ring 84is adjusted to a position wherein the lower beveled edge face 86 of thering is disposed to intercept only the upper portions of the emergingstreams. When the sprinkler head is adjusted for minimum flow rate, asin FIG. 11, that portion of the stream issuing from each orifice 16which impinges against the underside 86 of the ring 84 is a relativelylarge proportion of the whole, and therefore the deflecting andspreading effect of the ring is at its maximum. On the other hand, whenthe head is adjusted for maximum flow rate, as in FIG. 10, that portionof the stream impinging against the ring 84 is a relatively smallproportion of the whole, and the deflecting and spreading effect of thering is consequently at its minimum. Thus, the ring 84 is effective onlyat low flow rates, when it is most needed, and at higher flow rates itsinfluence is negligible. As noted earlier, the deflector ring 84 ispreferably adjustable relative to the spray head cap 36, so that it maybe positioned for optimum dispersion of the emerging water streams underany given minimum water pressure and flow rate conditions, although itis also contemplated that the ring 84 might be molded integrally withthe cap body 48.

It is evident that, when the spray head 10 has a full 360 spray pattern,it is immaterial whether or not the spray head cap 36 rotates relativeto the housing 24 during operation of the sprinkler. However, when thespray head has less than a full 360 spray pattern, as in the case of theembodiments shown in FIGURES 7 through 9, it is essential that the capbe restrained against rotation relative to the housing. This isaccomplished by having the notch 101 in the lower spray head shoulder 44engage the rib 102 of the strainer 34, which effectively keys the sprayhead against rotation relative to the sprinkler housing 26. Thefrictional engagement of the spray head cap 36 in the counterbore 46 ofthe spray head body 38 restrains the cap against rotation relative tothe spray head body.

While I have shown and described in considerable detail what I believeto be the preferred form of my invention, it will be understood by thoseskilled in the art that various changes may be made in the shape andarrangement of the several parts without departing from the scope of theinvention.

I claim:

1. An irrigation sprinkler head comprising slidably telescoping innerand outer members having opposed edges which cooperate to define agenerally triangularlyshaped discharge orifice in the side of saidsprinkler head,

through which a stream of water is discharged in a radial direction;

said outer member comprising a generally tubular body containing apasageway connected to a source of water under pressure, said passagewaybeing open at one end of said body;

said inner member comprising a cap having an open cylindrical endfitting slidably within said pasageway, and an opposite closed end;

said open cylindrical end having a generally V-shaped openingcommunicating with said passageway and having an apex extending axiallybeyond said one end of said body to define two sides of said triangularorifice;

said outer member having an annular edge at said one end thereofextending acros ssaid opening to define the base side of said orifice;and

means for axially adjusting said cap relative to said body for thepurpose of varying the eifective area of said orifice without alteringthe geometric proportions thereof.

2. An irrigation sprinkler head according to claim 1, wherein said opencylindrical end of said cap has a plurality of circumferentially spaced,generally V-shaped openings communicating with said passageway, the apexends of which extend in the same axial direction of said members beyondsaid one end of said outer member; and

said annular edge of said outer member extending across all of saidopenings to define the base sides of said orifices.

3. A sprinkler according to claim 2, wherein:

said body includes as tubular stem extending coaxially beyond said oneend thereof;

said cap has a central bore slidably receiving said stern and a sleevedefining said bore and surrounding said stem;

said sleeve has an externally conically tapered surface defining withsaid body an annular, axially tapered inlet to said orifices; and

said orifice adjusting means comprise a screw carried by said cap andthreaded in said stem.

4. A spray head according to claim 1, including:

a deflector on said spray head above said orifice and having a loweredge projecting across the apex end of said orifice exit section.

5. A spray head according to claim 4, wherein:

said deflector comprises a ring threaded on said spray head for axialadjustment relative to said spray head.

6. A pop-up sprinkler comprising:

a tubular housing having a lower water inlet and an axial openingthrough its upper end;

a spray head axially slidable within said opening between a retractedposition wherein the upper end of said spray head is substantially flushwith the upper end of said housing, and an extended position whereinsaid spray head projects above said housing;

said spray head comprising a lower tubular body having a passagwayopening to the interior of said housing, and a cap coaxially disposed atthe upper end of said body, said cap having a lower end slidably fittedin the upper end of said body and an upper closed end;

said cap having a number of circumferentially spaced,

generally V-shaped openings having apex sides extending axially beyondsaid upper end of said body to define a plurality of substantiallyidentical discharge orifices;

said spray head body having an upper annular edge extending across saidopenings to define the base sides of said orifices, each of saidorifices having an effective exit section of generally triangular shapebounded on two sides by the converging sides of said V-shaped openingsand on the base side by said annular edge;

orifice adjusting means for effecting simultaneous relative adjustmentof the respective orifice apices and base sides toward and away from oneanother to vary the axial spacing therebetween and thereby the effectiveareas of said exit sections without altering the geometric proportionsof said exit sections, comprising means for axially adjusting said caprelative to said body;

means for limiting axial movement of said spray head relative to saidhousing between said retracted and extended positions; and

means for yieldingly retaining said spray head in said retractedposition, whereby said spray head is extended by water pressure in saidhousing.

7. A sprinkler according to claim '6, wherein:

said housing includes a lower, generally cup-shaped body and an uppercap threaded on the upper end of said body;

said housing opening extends centrally through said cap; and

said sprinkler further comprises a generally cup-shaped strainercoaxially disposed within said housing in surrounding relationship tosaid spray head, and having an upper, radially outwardly directed flangeclamped between said housing cup and cap to form a seal therebetween 8.A sprinkler according to claim 6, wherein:

a deflector ring surrounding said cap above said orifices and having alower annular edge extending across the apex ends of said orifices;

said orifices and deflector ring being disposed within said housingopening when said spray head is in said retracted position; and

means for axially adjusting said deflector ring relative to said cap.

9. A pop-up sprinkler comprising:

a housing including a lower, generally cup-shaped body and a capthreaded on the upper end of said body; said cap having a centralopening extending therethrough;

a spray head slidable in said opening between a retracted positionwithin said housing wherein the upper end of said spray head issubstantially flush with the upper surface of said cap, and an extendedposition wherein said spray head projects a distance above said cap; and

a generally cup-shaped strainer coaxially disposed within said housingand surrounding said spray head, said strainer including an upper,radially directed flange clamped between said housing body and said cap.

References Cited UNITED STATES PATENTS 1,853,805 4/1932 Elder 2392052,075,589 3/1937 Munz 239-204 X 2,125,978 8/1938 Arbogast 239204 X M.HENSON WOOD, JR., Primary Examiner.

MICHAEL Y. MAR, Assistant Examiner.

US. Cl. X.R.

